The long-term goal of this project is to increase our understanding of synaptic communication in the nervous system. The molecular mechanism by which neurotransmitters are released at chemical synapses is still not resolved. However, it is known that calcium channels of nerve endings are vital for regulating this process. This work directly addresses questions concerning the structure and properties of presynaptic calcium channels, and it will lead to the production of reagents that should be of long-term utility for studying these proteins. Specifically, this project entails the production of monoclonal and polyclonal antibodies against a candidate subunit of a presynaptic calcium channel that was recently cloned by this laboratory. These antibodies will be used to purify this protein and other candidate calcium channel subunits. These antibodies will also be used for the immunolocalization of this antigen in tissues and subcellular fractions. These investigations should dramatically improve our knowledge of presynaptic calcium channels and how they contribute to normal synaptic function. This is a crucial prerequisite for applied studies of how these channels are modulated by environmental and genetic factors in health and disease.